A BLADE FOR A MIXING DEVICE

Abstract: Blade for a mixing device, especially for the mixing of different particles or different liquids, for the arrangement on substantially horizontal rotors, where each blade comprises a first surface with a curvature facing the direction of the motion for the particles and in the radial direction the blades shape has straight lines arranged perpendicularly to the rotor axis, where the curved blade comprises a first portion (3) facing in the direction of motion of the masses, a second, substantially smaller portion (4) facing opposite the direction of motion, and a portion lying in between and connecting the two aforementioned portions, extending substantially parallel with the rotor axis, in such a way that the substantial portion of the masses are thrown forwards, whereas a smaller portion is thrown radially outwards and respectively backwards, the particles thereby being mixed with particles being thrown forwards from the following blade.

Description: A Blade for a Mixing Device The present invention is related to a blade for a 5 mixing device, according to the preamble of the claims. Mixing devices of this kind are used within a number of fields for mixing two or more different substances of particles or liquids or a combination of such, to a desired degree of homogeneousness. The different substances are supplied in amounts 0 which are metered to a specified degree. Such substances may be tow or more liquids to be mixed, two or more particles or particles to be added and mixed with liquids. The substances to be mixed have greater or smaller differences in nature and condition. s Such mixing devices also are used for drying or freezing particles, set out as separate processes or as part of a mixing process. Mixing devices of the above mentioned type normally operate with blades or shovels secured to two parallel rotors, o rotating in opposite direction. The shape and the arrangement of the blades causes the masses to be thrown up thereby to be mixed and simultaneously transported forwards in the mixing device. It here certainly is important that the so-called casting curvatures is optimized, thereby to achieve the best possible mixing 5 simultaneously with the desired forward transportation. Well known are flat blades arranged in different positions on the rotor axis. There has since long further been made attempts to change the angle of the blades in relation to the rotor axis, as well as other parameters such as the number o of revolutions, the length of the blades etc., to optimize the mixing process. It has now been found that the mixing process may be further optimized by means of amending the shape of the blades, simultaneously also other advantages are achieved. 5 These advantages are achieved with the blade according to the present invention as defined with the features stated in the claims. In the drawing figure 1 discloses schematically a mixing device having two rotors, in an axial view, figure 2 discloses a side view towards the rotor axis of one blade form and figure 3 discloses a corresponding view of a modified blade form. By forming a blade 1 for example as part of a circular s pipe, such pipe conveniently may be divided into four segments, each corresponding to 90° and where each segment is secured to the rotor as disclosed in figure 2, turned an angle a in relation to the rotor axis. The angle α suitably may be 20° which means that part of the masses are influenced by the front part 3 of the o blade and one part is influenced of the rear part 4. The curved form of the blade provides a substantial dispersal of the masses being thrown up and partly also a transportation backwards in relation to the transportation direction of the mixing device, namely of the masses which are influenced of the rear part 4. s The outer circumference of the blade suitably is bent up to a flange 2 or a flange 2 is secured to the blade, as a continuous curvature or as a obtuse angle to the blade. Masses which are thrown radially outward along the blade 1, hit the flange 2 and thereby change their casting path. o Furthermore it is important that the mass thrown radially outwards along the blade 1 to a high degree will hit the flange 2 and thereby change its direction instead of hitting the bottom of the container of the mixing. This means that the wearing of the bottom of the container is decreased, which is of substantial 5 importance, depending on the masses used in the process. Figure 3 discloses che atically another embodiment of a curved blade, namely in a cross section not as a part of a circle, but as a curved surface where the rear part 4 still is maintained to achieve a larger distribution of masses, also o stationary and partly backwards in relation to the rotor axis and the transportation direction. As it is disclosed in the drawing it is further important to maintain a blade with a curvature thereby to achieve a large distribution of the masses and an optimized, high casting curvature 5, as disclosed in figure 1. 5

Claims: P a t e n t C l a i m s 5 1. Blade for a mixing device, especially for the mixing of different particles or different liquids, for the arrangement on substantially horizontal rotors, where each blade comprises a first surface with a curvature facing the direction of the motion for the particles and in the radial direction the blades ιo shape has straight lines arranged perpendicularly to the rotor axis, CHARACTERIZED IN the curved blade comprising a first portion (3) facing in the direction of motion of the masses, a second, substantially smaller portion (4) facing opposite the direction of motion, and a portion lying in between and connec- i5 ting the two aforementioned portions, extending substantially parallel with the rotor axis, in such a way that the substantial portion of the masses are thrown forwards, whereas a smaller portion is thrown radially outwards and respectively backwards, the particles thereby being mixed with particles being thrown 20 forwards from the following blade. 2. Blade according to claim 1, CHARACTERIZED IN the outer circumference of the blade comprising a flange (2) which creates an obtuse angle with the rest of the blade in a radial direction, pointing in the direction of motion and which extends 5 substantially along the entire axial length of the blades. 0 5

Inventors: NORDAHL GEIR, NORDAHL, GEIR
Applicants: NORDAHL GEIR, NORDAHL, GEIR
Application year: 1994
Main classification: B01F7
IPC codes: B01F7, B01F15